In order to make a proper interpretation of the analytical data for the water of the Guayama Aqueduct, as shown in Table No. 7,1 samples were obtained from the same locality and from sources supposed to be pure, so as to place these figures as standards for that locality.

The following tables give the maximum and minimum figures for the Guayama Aqueduct embracing a period from August, 1914, to June, 1915, and for the purpose stated:

The water from the Guayama Aqueduct is fairly clear, as is shown by the turbidity being kept almost constantly under 100. The total solids were very variable, although in moderate amount. The hardness shows a great variation from soft to hard water, although it is most of the time a soft water. The chlorine, nitrates, nitrites, oxygen consumed, free and albuminoid ammonia seem to indicate that it is polluted from time to time, and thus is especially noticeable on the 31st of August and on the 21st of September, as is shown in Table No. 7.1

Adequate means must be put into action to discover the real source of this pollution, which may be dangerous if some disease germ finds its way into the water.

It will be instructive also to compare the figures of Table No. 71 with the bacteriological examinations made during the same period of time by the biological laboratory of this service.

For the purpose of comparing standard figures with the water of the Mayaguez Aqueduct a few samples were selected from the same locality.

The following give the maximum and minimum results as obtained from Table No. 8 for the water of the Mayaguez Aqueduct and for the purpose of study:

The appearance of the water from the Mayaguez Aqueduct was generally very turbid, especially from August to November, 1914; during the month of December the turbidity was variable; but in January, February, March, April, and part of May it was very clear, except at intervals when affected by rain. During the rest of May and part of June it was also turbid most of the time. The total amount of solids were somewhat variable although never excessive. The hardness ran within wide limits, from soft to hard water. The chlorine, nitrates, nitrites, oxygen consumed, free and albuminoid ammonia, show so wide variations as to indicate contamination from time to time, as when the complete analytical data is compared in Table No. 8.1 Following the rule established since the beginning of this report, a few samples were selected from the district of Ponce, during the same period of the investigation,

1 Table omitted; copy on file.

from streams supposed to be pure, to compare said standard figures with those given in Table No. 9.1

The maximum and the minimum figures as selected from Table No. 9,1 for the water of the Ponce Aqueduct and for the purpose of study, are also given.

The turbidity was very low and fairly constant during the period of the investigation. The amount of total solids was variable but moderate. The hardness ran within wide limits, from moderately soft to hard water. The amount of chlorine, nitrates, nitrites, oxygen consumed, free and albuminoid ammonia, taking the complete analytical data as a whole, show a wide variation pointing to some sort of contamination, perhaps an intermittent contamination, which may be traced and eliminated. The results of the analyses of a few samples of water collected in the same district where the supply for the Caguas Aqueduct is established, and from streams supposed to be pure are given in order to take such figures as standards for that locality. The maximum and the minimum figures as selected from Table No. 10,1 are stated further for the purpose of study of the water of the Caguas Aqueduct:

The amount of total solids is fairly constant. The hardness runs within narrow limits from soft to moderately hard. The amount of chlorine, nitrates, nitrites, oxygen consumed, and free and albuminoid ammonia, comparing each complete analytical data with those made in previous or in later dates, show also an intermittent contamination which must be traced by some proper way; this being especially noticeable in the samples collected on the 31st of August and 28th of September, 1914.

BIOLOGICAL LABORATORY.

Dr. I. González Martinez, Director.

The work carried out in the biological laboratory during the past fiscal year is shown in a condensed table, which is hereto attached, and marked No. 11. The routine work of this laboratory shows a very noticeable and rapid increase, there having been examined in the laboratory during the fiscal year 1912-13, 4,745 specimens; in 1913-14, 5,953; and in 1914-15, 6,128.

In spite of this increase in the routine work, and in addition thereto, there were carried on under the direction of Dr. Gonzáles Martínez, director of this laboratory, the following special studies: (1) A systematic bacteriological analysis of the water

1 Tables omitted; copies on file.

supplies of certain of the most important towns of the island; (2) the bacteriological diagnosis and treatment of leprosy; and (3) a comparative study of the different methods of serum diagnosis of syphilis.

(1) The report of the bacteriological analysis of the water supplies will be shown in connection with the reports of the other officers of the service who took part in this special work.

(2) The diagnosis and treatment of leprosy.-From the beginning of June, 1914, and before having knowlenge of the work carried on by Ribas in Philadelphia, Dr. González Martínez had worked out a method of investigation of the bacillus of Hansen in the blood of anæsthetic lepers in whom no result had been obtained from the analysis of the nasal secretion and from the exudates obtained from amputating or deforming ulcerations. This procedure consisted in extracting blood from a vein which was collected in two centrifugation tubes, one of these filled two-thirds full of sterile redistilled water and the other emptied and sterilized in an oven, exactly as the tubes are prepared for the collection of blood for the Wasserman reaction. In the first the water produced a hemolysis of the erythrocites and when this was completed the bacillus of Hansen was sought for in the centrifugated sediment by the coloring methods of Ziehl-Nelson and Pappenheim. In the second tube was produced the formation of a coagulum and natural separation of serum in the ice box. Twenty-four hours afterwards the serum was decanted and the coagulum, which in nets of fibrine must have caught the bacilli, was destroyed by a solution of antiformine, centrifugated, and the residue submitted in cover glasses to the specific coloring matters above mentioned. A number of samples were examined which had been obtained from anaesthetic lepers confined in the leper colony only upon the clinical diagnosis because of the repeated failure in the microscopical examination of the nasal secretion and exudates from ulcerations. The result was brillant. In all, without exception, the groups characteristics of the bacillus of Hansen were found. Since that time this method of bacteriological examination of leprosy is employed as a routine matter in this laboratory. It is proper to state that our procedure is entirely free from error in the sterile water or in the solutions employed to dissolve the coagulum for the reason that besides the extreme care taken in using only water known to be pure, at the same time, as a counterproof, the same investigation was practiced in the coagulum of all the samples of blood which had been received on the same day for the investigation of Wasserman reaction, proceeding from persons known to be free from leprosy. In none of these cases was there found anything which might in any way resemble the Hansen bacillus. The hypodermatic treatment of leprosy with Chaulmoogra oil according to the method employed by Mercado in the Philippine Islands was only applied to seven sick chosen from those more severley attacked in our leper colony. It was not possible to carry it out on a greater scale because of the many deficiencies which exist in this establishment and the great difficulty caused by its being located on a small island, a long distance from the laboratory, rendering impossible the frequent visits which it would have been necessary to make. Nevertheless it can be stated that the result was relatively good, since two of those treated improved notably. It would be a matter of regret that this promising medication should not be continued.

(3) The serum diagnosis of syphilis.-The contradictory results which in many cases have been obtained from a serum reaction of Wasserman in the hands of experts attracted the attention of Dr. González Martínez and induced him to make a careful study of the different methods for the complement fixation in the cases of syphilis. It is impossible in this brief report to treat extensively this question, and it is necessary therefore to limit it to state concisely the conclusions arrived at by him after he had practiced 671 serum reactions according to the original method of Wasserman and the modifications introduced in it by Noguchi, Desmouliere, Weimberg, and Hetch. (a) Before interpreting a Wasserman reaction the physician should consider the analyst who made the examination and his capacity as an investigator. The personal equation here having as great an influence as the quality of the reagents employed. (b) It is preferable to give a negative verdict in cases of syphilis clinically positive rather than to put the stigma of syphilis on persons free from that disease.

(c) For that reason the analyst should ignore as far as possible the clinical diagnosis of the case. In that way he will proceed to the investigation without any previously formed opinion.

(d) Do not put any confidence in those investigators who pretend to obtain a positive reaction in every case of syphilis. They will fall into error more easily than those who adopt the opposite conduct.

(e) The original method of Wasserman is excellent when the investigator takes care to eliminate those cases classified as weakly positive, submitting them to proofs by elimination.

(f) The technic of Noguchi practiced with reagents dried on paper is an impossibility in tropical countries. The hemolitic force of the amboceptor varies from day to day. When a liquid amboceptor is used prepared in the country and its special antigen, it gives a procedure which is excellent and easily carried out.

is

(g) For obscure cases of syphilis or for ocular syphilis the technic of Desmouliere recommended as even better than that of Weimberg and Hetch.

It is a matter of extreme regret that the necessity of economy in the expenditures of this service necessitated a reorganization of the bureaus in this office so that the biological laboratory had to be united in the future to the bureau of transmissible diseases.

In this reorganization the sanitation service lost the exceedingly valuable assistance of Dr. González Martínez who had organized the laboratory and who had been in charge since the original organization of this service.

His professional abilities, however, will be preserved to the government, through his membership in the Institute of Tropical Medicine where he will have the opportunity to carry on the original investigations for which he is so eminently fitted.

CHEMICAL LABORATORY.

Dr. R. Del Valle Sarraga, Director.

The following report comprises in tabular form a summary of all analyses of foods, drugs, and other materials submitted to chemical investigation by the various branches of the insular government, during the fiscal year ending June 30, 1915.

Table No. 12' gives the work performed in this laboratory during said fiscal year. Table No. 131 states the source of samples.

Table No. 14 contains the classification of cases recommended to the district courts for prosecution.

Table No. 15' comprises the distribution of samples as classified each month. Table No. 161 includes the number of samples of water analyzed each month during the special water investigation.

Table No. 17 shows the distribution of good and adulterated milk for the various towns of the island, according to samples secured by the inspectors of these towns. Table No. 18 shows the amount of food destroyed.

The tremendous amount of work performed during the fiscal year has more than doubled the figure stated in last year's report. The total number of samples analyzed for the 12 months ending on June 30 last, amounts to 2,547 samples and that of the previous fiscal year to 1,103 samples examined.

In spite of the penalties fixed by our law, fines being excluded and only jail penalties imposed, the percentage of adulteration of milk has increased from 11.98 per cent for the fiscal year ending 1914 to 21.20 per cent for the fiscal year 1914-15. This fact shows that there exists in the milk trade a certain tendency to adulterate milk with water, no matter what restrictions are provided by legislation. The causes of this evil, the worst form of food adulteration, must be properly investigated in order that they may be eliminated.

Some research work has been made with various brands of condensed and evaporated milk, to determine the proper methods and individual tests that may show the presence of such products as adulterants of fresh cow's milk when the vendor attempts to conceal from the chemist that it has been adulterated with water. The investigation has not been sufficiently advanced to warrant conclusions or to show definite figures. The bread sold during the year has been of an inferior quality most of the time. The condemnation of such bread has been based on the accurate titration of acidity and the physical examination as to taste and the proper cooking. The appearance of the crumb was also taken into consideration before deciding as to its quality. The investigations made in the bakeries by our chemists and inspectors show that the dough is not properly mixed and that the ferment, used to make it rise, is generally contaminated with germs and yeast of all kinds by transplanting the yeast, from day to day, to the dough that remains to be worked up for the following day. This contamination results from the introduction of bacteria into the dough from the hands of the bakers or the utensils used in such establishments and from the street dust falling on unprotected receptacles where the dough is stored as a "culture" for future operations. The result of such unsanitary processes is the production of an excessively acid bread that at times has a sharp, bitter taste.

Wheat and corn flours have been contaminated frequently with worms and weevils and a certain discretion has been used before condemning the lots inspected. During the coming year the inspectors will keep a close watch on flours so contaminated in

1 Tables omitted; copies on file.

order to carry a case into court to determine to what limit this contamination may be permitted without violating the pure-food act.

Raw coffee grains have been found coated with substances that may be deleterious to health. A complete investigation will be made and when the complete evidence is obtained we will act accordingly. An investigation is under way of the adulteration of ground coffee with cereals, a very common practice on this island.

An investigation of California wines has been started on a large scale, as they are largely diluted with water and alcohol and then sold at lower prices than the original ones stated in the invoices secured.

A complete examination has been made of the gasoline used as fuel and sold in the markets of the island, to serve as a basis for proper legislative action. This also includes the fractional distillation of all samples.

Ice has also been investigated, to determine to what extent the brine, for freezing purposes, contaminates the final product through leaking in the molds.

A certain amount of work has been performed on patent medicines and special attention has been paid to the "Antifimic Balsam" which is widely advertised as a cure for tuberculosis. Many drugs have been examined by securing small samples from independent purchasers. The public has cooperated with the inspectors. In this way we have found mercuric red oxide largely adulterated or wholly substituted by red lead, and calomel ("sold for external use only") largely adulterated or wholly substituted by lead carbonate.

A large amount of work has been performed for the bureau of internal revenue and for the department of justice; the latter was especially helped a great deal by our chemists, who gave great assistance as experts, presenting evidence in various criminal cases in which legal chemistry could play a part in throwing light upon the subject. By inspecting closely Table No. 13 it will be found which towns cooperated with the food and drug law and to what extent they did so. The sanitary authorities of the city of Ponce sent in more samples than any other town on the island.

It will be noticed that in this table is given the number of samples as supplied monthly by all towns.

Attention is respectfully called to Table No. 14 as to the status of cases pending prosecution in the various district courts of the island for adulteration of milk, and which has been outlined in accordance with the partial reports obtained from said

courts.

The valuation of all food destroyed, as shown in Table No. 18, has been estimated at approximately $22,658.

DIVISION OF VETERINARY INSPECTION.

Dr. Juan Varas Catala, Veterinary Inspector. Dr. Jaime Bague, Veterinary Inspector.

I have the satisfaction of reporting that the disease of horses and mules known as glanders is steadily decreasing on the island. In the fiscal year 1914-15, 62 horses and mules were killed because suffering from glanders. These diagnoses were proven by the complete fixation test and seven cases more diagnosed clinically, as the symptoms were so typical as to need no further proof. The latter were killed, after having obtained the written consent of the owners.

In the fiscal year 1914-15, 133 horses and mules having glanders were killed, making a decrease of 64 animals killed in the past fiscal year, the percentage infection being decreased from 0.96 in 1913-14 to 0.59 in 1914-15. This demonstrates that the work of the veterinary inspectors is giving the result desired by the sanitation service, namely, to stamp out glanders on the island. In order to do this, it is not only necessary to continue the previous work, aided by the positive diagnosis of the fixation test, but also to require that horses, mules, and burros, when imported, should be accompanied by mallein charts filled out by the official veterinarians of the countries exporting them, or by some other proof that they are not suffering from glanders.

This procedure has been followed in Hawaii, giving such wonderful results that at present there is no glanders there. If this were done on the island of Porto Rico, glanders would be eradicated in a few years. It is to the interest of the owners of horses, mules, and burros that these steps be taken. If impossible to do this, then the veterinary inspectors of this service should apply mallein test to all horses, mules, asses, or other related animals, when imported, as soon as they have been landed.

FOOT-AND-MOUTH DISEASE.

Due to the orders given to the steamship companies not to introduce ruminants or swine from the United States during the epidemic of foot-and-mouth disease in that country, we have had the good fortune of having been free from this disease on the